Do You Need Makeup Air for Your New Range Hood?

Your lack of makeup air might be the next reason your home does not pass inspection.

A code from 2009 dictates kitchen range hoods with exhaust rates of 400 CFM or greater must have makeup air, or replenishment air, added back into their homes to replace the oxygen exhausted outside.

The need for makeup air has become more and more relevant as newer homes allow less and less air to enter or escape. A 400 CFM hood was not likely to suck out all of the oxygen in an older, drafty home, but in today’s energy efficient, virtually airtight homes, high powered hoods can and are dangerous.

Specifically, makeup air significantly reduces the risk of carbon monoxide poisoning. Without the addition of makeup air, air pressure can eventually drop causing a back draft to occur, which then creates a vacuum that inhibits carbon monoxide (from the gas range, furnace and water heater) from venting outside. Carbon monoxide can then reach unsafe levels that even lead to death.

So yes, you probably need makeup air if you want a powerful range hood.

If adding makeup air is not feasible or too costly, then look into Zephyr’s hoods with Airflow Control Technology (ACT). Exclusive to Zephyr, the feature allows the exhaust rates of their hoods at the time of install to be lowered to 390 CFM, which is safe and to code, and still a powerful ventilation option. The only downside? It can’t be reversed. 

Find the right makeup air by Zephyr on Contract Appliance. Contact us if you have any questions.